In recent years, vinyl sulfonic acid has attracted increasing attention as a monomer for use in composing performance polymers or conductive materials.
There are various methods for producing vinyl sulfonic acid (see Nonpatent-Document 1); however, existing methods are still not reliable enough for the industrial production of vinyl sulfonic acid.
For example, Patent-Document 1 discloses a method for producing vinyl sulfonic acid by removing sodium from sodium vinyl sulfonate using hydrochloric acid.
However, this method fails to ensure desirable product quality. Moreover, distillation of the vinyl sulfonic acid manufactured by this method produces a large amount of solid residue. For these reasons, this method is almost useless for industrial purposes.
Patent Document 2 discloses a method for producing vinyl sulfonic acid via dehydration of an isethionic acid using phosphorus pentoxide or pyrophosphoric acid as a dehydration agent. However, this method uses a large amount of dehydration agent, and requires disposal of the dehydration agent. For this reason, this method is not suitable for industrial purposes.    Patent-Document 1: U.S. Pat. No. 3,312,735    Patent Document 2: U.S. Pat. No. 2,597,696    Nonpatent-Document 1: Sango Kunichika, Takao Katagiri, Journal of the Chemical Society of Japan, Industrial chemistry section, Vol. 64 No. 5, 1961, pp. 929-932